Printing-form.



PATENTED DEC. 29, 1903.

. G. PANOOAST. PRINTING FORM.

APPLICATION FILED JAN. 27. 1900.

,1. ummumn $4 ATTORNEY-S Patented December 29, 1903.

UNITED STATES PATE T OFFICE.

GEORGE E. PANCOAST, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE AMERICANLITHOGRAPHIO COMPANY, A CORPORATION OF NEW YORK.

PRINTING-FORM.

SPECIFICATION forming part of Letters Patent No. 748,004, dated December29, 1903.

Application filed January 27, 1900. Serial No. 8,013. (No model.)

To aZZ whom it may concern:

Be it known that I, GEORGE E. PANCOAST, a citizen of the United States,and a resident of Brooklyn, in the county of Kings, State of New York,have invented certain new and useful Improvements in Printing-Forms, ofwhich the following is a specification.

My invention relates to printing-surfaces, and especially tolithographic orplanographic printing surfaces.

The object of the present invention is to provide a printing-surfacewhich shall be free fromsome of the disadvantages inherent in thelithographic or planographic printing surfaces now in general use.

Heretofore limestone of a peculiar quality has been almost exclusivelyused as the printing-surface in practical lithographic or planegraphicprinting. The inception of the art consisted in the discovery of, andits development and practice are based upon, the following facts orprinciples: First, when an ink containing a compound consisting of afatty acid and alkali combined, as in ordinary soap, is applied to thesurface of a stone and the stone is then treated with an acid which willdecompose the stone, to a slight extent, at least, the portions of thestone which were touched by the soapy substance become permanentlyrepellent to. wa-

ter, or, in other words, when allgrease has been removed fromlthesurface of the stone those portions thereof so treated readily takeprinting-ink even in the presence of water or moisture; second,when astoneis treated with a solution of gum-arable and an acid which willattack the stone those portions of the surface of a stone so treatedacquire an affinity for Water which is permanentl-hat is to say, whilesuch portions of the stone will take printing-ink when dry they willretain such ink only as long as kept dry. While a temporaryprintingsurface may be formed upon stone without the use of a soapy inkor substanceand withoutthetreatmentwithgum and an acid which willdecompose the stone, the proper employment of all these materials isessential to'ihe production upon stone of a permanent printing-surfaceof a practical character.

posed by acids.

The porosity of the lithographic stone is also an importantcharacteristic thereof for the production of a permanent lithographicsurface. The substances forming the inkrepellent and water-repellentportions of the printing-surface become more or less embodied in thepores of the stone or incorporated with the particles or granulesforming the surface thereof, and are consequently more permanentlyretained on the stone. The porosity of the stone also enables it tocarry sufficient water to keep its surface moist and snfficient ink togive good impressions without an excessive application of either ofthese substances for each printing operation.

Owing to the limited supply of stone suitable for lithographic purposes,and especially to the scarcity of perfect specimens of the larger sizes,such as are required for economical multicolor lithographic printing,and owing also to'the bulk and unwieldiness of stone printing-surfacesand to their fragile character and to their limitations as to shape,many attempts have been made to find a practical substitute therefor.Substances have been heretofore rejected, however, as unfit forlithographicprinting purposes unless they possess chemical propertiessimilar to those of lithographic stone-mamely, a capability of being soetched with an acid that the portions of the surface carrying a soapysubstance will become permanently repellent of water and the portions ofthe surface untouched by the soapy ink will become permanently repellentof printing-ink in the presence of water. Porosity or grain has alsobeen recognized as a very desirable, if not an essential, quality in apractical substitute for the stone printing-surface. These qualities insubstitutes for stone printingsurfaces have been best realized inelectrodeposited zinc and in pure aluminium. The zinc surface, however,possesses the disadvantage of being quickly oxidized upon exposure tothe air, and it is too readily decom- Aluminium, on the other hand, isdifficult to obtain in a sufficiently pure condition and in sheets orplates having a uniform texture of the proper density tov form goodprinting-surfaces. Both of these materials, moreover, when suitablyprepared are soft, and printing-surfaces formed thereon are verysensitive and-short-lived and require careful and delicate manipulation.

An object of the present invention is to provide a substitute forlithographic stone which does not have the defects above mentioned, butwhich is equally good, if not better, than zinc or aluminiumin otherrespects.

To this end my invention consists in the discovery that when acomparatively hard and tough metal, such as copper or nickel or silver,is produced under proper conditions a surface having a line, and yet anopen or porous, grain is formed, which can be developed intoaplanographic-printing surface of a very fine quality. I have found thata surface having the required grain or porosity may be produced by theelectrodeposition of any such metal if a sufficiently heavy deposit ofthe metal can be obtained. The weight of the deposit is not the onlycontrolling element in obtaining the required grain, however, as thenature of the surface produced is largely affected by the character ofthe bath and also by its manipulation. The work of obtaining therequired weight or thickness of deposit varies greatly, moreover, withthe various metals and with different baths of the same metal, as willhereinafter more clearly appear. Not only may the ingredients of theplating-bath for any particular metal be varied, but the strength of thecurrent used and the period of its application-may also be greatlyvaried, it only beingfimportant to note that in general the more rapidthe deposit is made the more even and uniform it will be. It is to beobserved that a very thin deposit of any metal, such as may bedetermined by the color of the deposit, will-be insufficient to form aprinting-surface. "To secure the essentials of grain or porosity ordepth of the surface, the deposit must have a substantial thickness,which, having been experimentally determined, may thereafter beaccurately reproduced by always maintaining the same condition andcharacter of treatment in the plating-bath. I have found, moreover, thatthe metal forming the surface does not need to have chemical propertiessimilar to-those of the lithographic stone and that it is not necessaryto employ in the etching solution used to develop the printingsurface anacid which will attack or decompose the'material forming the surface.

In the accompanying drawings are illustrated two forms ofprinting-surfaces embodying my invention.

Figure I is a perspective view of a flat printing-forinprovided with asurface made in accordance with my invention. Fig. 2 is a transversesection of thesame. Figs. 3 and at are similar views of a cylindricalprintingform embodying my invention.

Whichever of the above-mentioned or similar metals is employed as thematerial of my liable to injury than other metals.

printing-surface it is preferably deposited in the form of a layer orcoating upon a base or a basic layer of a difierentmaterial andpreferably a material ofa different color and having difierent chemicalproperties from that of the coating in order that the coating may bereadily removed without removing any substantial part of the material ofthe base, the

object in this being to renew the printing.

surface upon the base for each new design and also when theprinting-surfaces are to be used for multicolor-printing to producesuccessive printingsurfaces of predetermined sizes,the characteristic ofeach of which as to size being determined by that of the base, all asmore fully set forthin the patent to Hett, No. 637,560, dated November21, 1899. The surface may be removed from the base in any suitableway-to wit, by mechanical or chemical means; mechanical, by stripping,cutting, abrading; chemical,by dissolving with a suitable agent or byelectrolysis.

Referring to the drawings in detail, A represents a flat base, which maybe-recessed, as shown,to make it as light as is compatible withsubstantial rigidity under the pressure .of printing.

a represents a coating having the characterislics of myprinting-surface. When it is desired to remove the coating by an acidwhich would attack the material of the base or when the desired graincannot be obtained except by a bath which would attack the material ofthe base, the latter is provided with a protecting layer or primarycoating b of material which is not attacked by such acid or bath. Whenthe printing-surfaces are used for multicolor-printing, they arepreferably curved and circuinferentially continuous and tubular and thinor shell-like, as shown in F igs. 3 and 4, in which A represents a thintubular cylindrical base, and a, a circumferentially continuous coatingthereon. The base A is preferably made of steel, as this metal ischeaper and can be more easily worked and is more durable and less Sincesteel is easily corroded by chemicals, however, the base A is providedwith a protective primary coating 1') of any suitable material. Thisprotective coating is preferably applied by electrodeposition; but toaccomplish this care should be taken to use a plating-bath which willnot attack the material of the base. I have foundthe following bath tobe suitable, to wit:

Solution A: Dissolve in three hundred pounds of warm water ten poundseightounces of sodium-carbonate crystals, add gradually eight poundstwelve ounces sodiumbisulfate crystals, then add with vigorous stirringeight pounds twelve ounces of neutral acetate of copper in smallportions.

Solution B: Dissolveteu pounds ten ounces of potassium cyanid in onehundred pounds of cold water.

-When solution A is cold, add solution B be used as a printing-surface.Since it is difficult, however, to obtain the desired grain with thisbath, I preferably employ it to form a protective coating only on thebase. This is accomplished by applying an electric current of about .1ampere per square inch of the portion of the base receiving the deposit.

for half an hour, more or less.

When it is desired to form a printing-surface of copper, I prefer toemploy a second plating-bath as follows, to wit: fourhundred poundsWater; sixty-two pounds sulfate of copper, 12 hydrometer test; sixteenpounds sulfuric acid, 15 hydrometer test. With this bath a current of .1ampere per square inch of the portion of the base receiving the depositapplied for three hours will produce a secondary coating of copperhaving a good,

grain. The strength of current and the period of the application thereofmay be varied between wide limits, however, Without deenty-five poundsof the double sulfate of.

nickel and ammonia. With this bath heated to a temperature of about 170Fahrenheit a current of.Ol5 to .02 ampere per square inch of the surfacereceiving the deposit applied for a period of four hours will give therequired grain. This nickel surface is a harder and more durable surfacethan the copper surface, and it is not so liable to injury by oxidationor by acids.

When the printing-surface is to be formed of silver, I preferably employa steel base.

protected with copper, as before described. To obtain on the baseasilversurface having the proper grain, the following bath may be employed, towiti To one thousand parts of water add 9.3 parts of chlorid of silverand then add an excess of potassium cyanid, or to one thousand parts ofwater add thirtyfour parts of cyanid of silver, 20.5 parts of cyanid ofpotassium, ninety-five per cent. pure, and fifty-five parts of sodiumcarbonate. With either of these baths a current of .05 to .1 ampere persquare inch of surface applied for a period of three or four hours willproduce the required grain. Printingsurfaces may be formed of othersimilar metals, as gold, platinum, iron, tin, &c., it only beingrequisite that a sufficient quantity of the metal be deposited and theproper character of treatment in the plating-bath be maintained to formthe required grained surface.

Any of these surfaces may be developed into planographicprintingsurfaces by the ordinary methods of fixing the designs upon stone orzinc or aluminium surfaces. I have found, however, that thenitric acidand gum solution used in etching stone gives slightly better results. Itis essential to use a soapy ink in transferring or otherwise applyingthe design to the surface and to employ in the etching or fixingsolution an acid which will act to so fix the ink in the pores of thesurface as to render the portions thereof which are touched by the inkpermanently repellent of water and which will also act to so fix the gumin the pores of the surface as to render the portions thereof which areuntouched by the soapy ink permanently repellent of ink in the presenceof moisture.

.sisting of a layer of hard metal, said layer having a substantialthickness and being formed under such conditions as to produce a toughand durable surface having a substantial depth of grain or porosity.

2. A plauographic-printing surface consisting of a layer of hard metal,said layer having a substantial thickness and being formed by thedeposition of the metal under such conditions as to produce a tough anddurable surface having a substantial depth of grain or porosity.

3. A planographic-printing surface consisting. of a layer of hard metal,said layer being formed by the electrodeposition of the metal under suchconditions as to produce a tough and durable surface having asubstantial depth of grain or porosity.

4. A planographic-printing surface consisting of a layer of hard metal,said layer having a substantial thickness and being formed under suchconditions as to produce a tough and durable surface having asubstantial depth of grain or porosity, which surface without mechanicaltreatment is adapted for use as a planographic surface.

5. A planographic-printing surface consisting of a layer of hard metal,said layer being formed by the electrodeposition of the metal under suchconditions as to produce a tough and durable surface having asubstantial depth of grain or porosity, which surface ICC withoutmechanical treatment is adapted for use as a planographic surface.

6. A planographic-printing surface consisting of a layer of materialwhich is not decomposed by the materials used in fixing a design on thesurface, said layer having a substantial thickness and being formedunder such conditions as to produce a surface having a substantial depthof grain or porosity.

7. A planographic-printing surface consisting of a layer of materialwhich is not decomposed by the materials used in fixing a design on thesurface, said layer havingasubstantial thickness and being formed by thedeposition of the material under such conditions as to produce a surfacehaving a substantial depth of grain or porosity.

8. A planographic-printing surface consisting of a layer of metal whichis not decomposed by the materials used in fixing a design on thesurface, said layer having asubstantial thickness and being formed bythe electrodeposition of the metal under such conditions as to produce asurface having a substantial depth of grain or porosity.

9. A planographic-printing surface consisting of a layer of materialwhich is not decomposed by the materials used in fixing a design on thesurface, said layer haviuga substantial thickness and being formed undersuch conditions as to produce a surface having a substantial depth ofgrain or porosity, which surface without mechanical treatment is adaptedfor use as a planographic surface.

10. A planographic-printing surface consisting of a layer of metal whichis not decomposed by the materials used in fixing a design on thesurface, said layer having a substantial thickness and being formed bythe electrodeposition of the metal under such conditions as to produce asurface having a substantial depth of grain or porosity, Which surface,without mechanical treatment is adapted'for use as a planographicsurface.

11. AZplanographic-printing surface consisting of a layer of copper,said layer having a substantial thickness and being formed under suchconditions as to produce a tough and durable surface having asubstantialdepth of grain or porosity.

12. A planographic-printing surface consisting of a layer of copper,said layer having a substantial thickness and being formed bytbe'electrodeposition of the metal under such conditions as to produce atough and durable surface having a substantial depth of grain 'orporosity.-

13. A planographic-printing surface consisting of a layer of copper,said layer having a substantial thickness and being formed by theelectrodeposition of the metal undersuch conditions as to produce atough and durable surface having a substantial depth of grain orporosity, which surface without mechanical treatment is adapted for useas a planographic surface.

14. A planographic-printing surface consisting of a base and a coatingof a hard metal, said coating having a substantial thickness and beingformed under such conditions as to produce a tough and durable surfacehaving a substantial depth of grain or porosity.

.15. A planographic-printing surface consisting of a base and a coatingof a hard metal, said coating having a substantial thickness and beingformed by the electrodeposition of the metal under such conditions as toproduce a tough and durable surface having a substantial depth of grainor porosity.

16. A planographic-printing surface consisting of a base and acoating ofa hard meta], said coating having a substantial thickness and beingformed by the electrodeposition of the metal under such conditions as toproduce a tough and durable surface having a substantial depth of grainor porosity, which surface without mechanical treatment is adapted foruse as a planographic surface.

17. A planographic-printing surface consisting of a steel base and acoating of copper, said coating having a substantial thickness and beingformed by the electrodeposition of the metal under such conditions as toproduce a tough and durable surface having a substantial depth of grainor porosity.

18. A planographic-printing surface consisting of a steel base and acoating of a material not decomposed by the materials used in fixinga-design on the surface, said coating having a substantial thickness andbeing formed under such conditions as to produce a tough and durablesurface having a substantial depth of grain or porosity.

19. A planographic-printing surface consisting of a base, a primaryprotective coating thereon, and a secondary coating of hard metalthereon, said secondary coating being formed under such conditions as toproduce a tough and durable surface having a substantial depth of grainor porosity.

2O. A planographic-printing surface consisting of a steel base having aprimary protective coating of copper thereon and a secondary coating ofhard metal thereon, said secondary coating being formed by theelectrodeposition of the metal under such conditions as to produce atough and durable sur face having a substantial depth of grain orporosity.

21. A planographic-printing surface consisting of a base, a primaryprotective coating thereon and a secondary coating of material which "isnot decomposed by the materials used in fixing a design on the surface,said secondary coating being formed under such conditions as to producea surface having a substantial depth of grain or porosity.

22. A planographic-printing surface consisting of a steel base having aprimary protective coating of copper thereon and a secondary coating ofcopper thereon, said secondary coating being formed by theelectrodeposition of the metal under such conditions as to produce atough and durable surface having a substantial depth of grain orporosity.

23. A planographic-printing form consisting of a hard material, saidmaterial being electrolytically deposited under such condi tions as toproduce a tough and durable surface having a substantial depth of grainor porosity.

24. A planographic-printing form consisting of a hard material which isnot decomposed by the materials used in fixing adesign on the surface ofthe form, said material be ing electrolytically deposited under suchconditions as to produce a tough and durable sur-

